package PDL::IO::HDF5::Group;
use Carp;
use strict;
=head1 NAME
PDL::IO::HDF5::Group - PDL::IO::HDF5 Helper Object representing HDF5 groups.
=head1 DESCRIPTION
This is a helper-object used by PDL::IO::HDF5 to interface with HDF5 format's group objects.
Information on the HDF5 Format can be found
at the NCSA's web site at http://hdf.ncsa.uiuc.edu/ .
=head1 SYNOPSIS
See L<PDL::IO::HDF5>
=head1 MEMBER DATA
=over 1
=item ID
ID number given to the group by the HDF5 library
=item name
Name of the group. (Absolute to the root group '/'. e.g. /maingroup/subgroup)
=item parent
Ref to parent object (file or group) that owns this group.
=item fileObj
Ref to the L<PDL::IO::HDF5> object that owns this object.
=back
=head1 METHODS
####---------------------------------------------------------
=head2 new
=for ref
PDL::IO::HDF5::Group Constructor - creates new object
B<Usage:>
=for usage
This object will usually be created using the calling format detailed in the L<SYNOPSIS>. The
following syntax is used by the L<PDL::IO::HDF5> object to build the object.
$a = new PDL::IO::HDF5:Group( name => $name, parent => $parent,
fileObj => $fileObj );
Args:
$name Name of the group (relative to the parent)
$parent Parent Object that owns this group
$fileObj PDL::HDF (Top Level) object that owns this group.
=cut
sub new{
my $type = shift;
my %parms = @_;
my $self = {};
my @DataMembers = qw( name parent fileObj);
my %DataMembers;
@DataMembers{ @DataMembers } = @DataMembers; # hash for quick lookup
# check for proper supplied names:
my $varName;
foreach $varName(keys %parms){
unless( defined($DataMembers{$varName})){
carp("Error Calling ".__PACKAGE__." Constuctor\n \'$varName\' not a valid data member\n");
return undef;
}
$self->{$varName} = $parms{$varName};
}
my $parent = $self->{parent};
my $parentID = $parent->IDget;
my $parentName = $parent->nameGet;
my $groupName = $self->{name};
my $groupID;
# Adjust groupname to be absolute:
if( $parentName ne '/') { # Parent is not the root group
$self->{name} = "$parentName/$groupName";
}
else{ # Parent is root group
$self->{name} = "$parentName$groupName";
}
# Turn Error Reporting off for the following, so H5 lib doesn't complain
# if the group isn't found.
PDL::IO::HDF5::H5errorOff();
my $rc = PDL::IO::HDF5::H5Gget_objinfo($parentID, $groupName,1,0);
PDL::IO::HDF5::H5errorOn();
# See if the group exists:
if( $rc >= 0){
#Group Exists open it:
$groupID = PDL::IO::HDF5::H5Gopen($parentID, $groupName);
}
else{ # group didn't exist, create it:
$groupID = PDL::IO::HDF5::H5Gcreate($parentID, $groupName, 0);
# Clear-out the attribute index, it is no longer valid with the updates
# we just made.
$self->{fileObj}->clearAttrIndex;
}
# Try Opening the Group First (Assume it already exists)
if($groupID < 0 ){
carp "Error Calling ".__PACKAGE__." Constuctor: Can't open or create group '$groupName'\n";
return undef;
}
$self->{ID} = $groupID;
bless $self, $type;
return $self;
}
=head2 DESTROY
=for ref
PDL::IO::HDF5 Destructor - Closes the HDF5::Group Object.
B<Usage:>
=for usage
No Usage. Automatically called
=cut
sub DESTROY {
my $self = shift;
#print "In Group DEstroy\n";
if( PDL::IO::HDF5::H5Gclose($self->{ID}) < 0){
warn("Error closing HDF5 Group '".$self->{name}."' in file '".$self->{parentName}."'\n");
}
}
=head2 attrSet
=for ref
Set the value of an attribute(s)
Attribute types supported are null-terminated strings and PDL matrices
B<Usage:>
=for usage
$group->attrSet( 'attr1' => 'attr1Value',
'attr2' => 'attr2 value',
'attr3' => $pdl,
.
.
.
);
Returns undef on failure, 1 on success.
=cut
sub attrSet {
my $self = shift;
# Attribute setting for groups is exactly like datasets
# Call datasets directly (This breaks OO inheritance, but is
# better than duplicating code from the dataset object here
return $self->PDL::IO::HDF5::Dataset::attrSet(@_);
}
=head2 attrGet
=for ref
Get the value of an attribute(s)
Currently the only attribute types supported are null-terminated strings.
B<Usage:>
=for usage
my @attrs = $group->attrGet( 'attr1', 'attr2');
=cut
sub attrGet {
my $self = shift;
# Attribute reading for groups is exactly like datasets
# Call datasets directly (This breaks OO inheritance, but is
# better than duplicating code from the dataset object here
return $self->PDL::IO::HDF5::Dataset::attrGet(@_);
}
=head2 attrDel
=for ref
Delete attribute(s)
B<Usage:>
=for usage
$group->attrDel( 'attr1',
'attr2',
.
.
.
);
Returns undef on failure, 1 on success.
=cut
sub attrDel {
my $self = shift;
my @attrs = @_; # get atribute names
my $groupID = $self->{ID};
my $attr;
my $rc; #Return code returned by H5Adelete
foreach $attr( @attrs ){
# Note: We don't consider errors here as cause for aborting, we just
# complain using carp
if( PDL::IO::HDF5::H5Adelete($groupID, $attr) < 0){
carp "Error in ".__PACKAGE__." attrDel; Error Deleting attribute '$attr'\n";
}
}
# Clear-out the attribute index, it is no longer valid with the updates
# we just made.
$self->{fileObj}->clearAttrIndex;
return 1;
}
=head2 attrs
=for ref
Get a list of all attribute names in a group
B<Usage:>
=for usage
@attrs = $group->attrs;
=cut
sub attrs {
my $self = shift;
my $groupID = $self->{ID};
my $defaultMaxSize = 256; # default max size of a attribute name
my $noAttr = PDL::IO::HDF5::H5Aget_num_attrs($groupID); # get the number of attributes
my $attrIndex = 0; # attribute Index
my @attrNames = ();
my $attributeID;
my $attrNameSize; # size of the attribute name
my $attrName; # attribute name
# Go thru each attribute and get the name
for( $attrIndex = 0; $attrIndex < $noAttr; $attrIndex++){
$attributeID = PDL::IO::HDF5::H5Aopen_idx($groupID, $attrIndex );
if( $attributeID < 0){
carp "Error in ".__PACKAGE__." attrs; Error Opening attribute number $attrIndex\n";
next;
}
#init attrname to 256 length string (Maybe this not necessary with
# the typemap)
$attrName = ' ' x 256;
# Get the name
$attrNameSize = PDL::IO::HDF5::H5Aget_name($attributeID, 256, $attrName );
# If the name is greater than 256, try again with the proper size:
if( $attrNameSize > 256 ){
$attrName = ' ' x $attrNameSize;
$attrNameSize = PDL::IO::HDF5::H5Aget_name($attributeID, $attrNameSize, $attrName );
}
push @attrNames, $attrName;
# Close the attr:
PDL::IO::HDF5::H5Aclose($attributeID);
}
return @attrNames;
}
=head2 dataset
=for ref
Open an existing or create a new dataset in a group.
B<Usage:>
=for usage
$dataset = $group->dataset('newdataset');
Returns undef on failure, 1 on success.
=cut
sub dataset {
my $self = shift;
my $name = $_[0];
my $groupID = $self->{ID}; # get the group name of the current group
my $dataset = PDL::IO::HDF5::Dataset->new( name=> $name, parent => $self,
fileObj => $self->{fileObj} );
}
=head2 datasets
=for ref
Get a list of all dataset names in a group. (Relative to the current group)
B<Usage:>
=for usage
@datasets = $group->datasets;
=cut
sub datasets {
my $self = shift;
my $groupID = $self->{ID};
my @totalDatasets = PDL::IO::HDF5::H5GgetDatasetNames($groupID,".");
return @totalDatasets;
}
=head2 group
=for ref
Open an existing or create a new group in an existing group.
B<Usage:>
=for usage
$newgroup = $oldgroup->group("newgroup");
Returns undef on failure, 1 on success.
=cut
sub group {
my $self = shift;
my $name = $_[0]; # get the group name
my $group = new PDL::IO::HDF5::Group( name=> $name, parent => $self,
fileObj => $self->{fileObj} );
return $group;
}
=head2 groups
=for ref
Get a list of all group names in a group. (Relative to the current group)
B<Usage:>
=for usage
@groupNames = $group->groups;
=cut
sub groups {
my $self = shift;
my $groupID = $self->{ID};
my @totalgroups = PDL::IO::HDF5::H5GgetGroupNames($groupID,'.');
return @totalgroups;
}
=head2 _buildAttrIndex
=for ref
Internal Recursive Method to build the attribute index hash
for the object
For the purposes of indexing groups by their attributes, the attributes are
applied hierarchial. i.e. any attributes of the higher level groups are assumed to be
apply for the lower level groups.
B<Usage:>
=for usage
$group->_buildAttrIndex($index, $currentAttrs);
Input/Output:
$index: Total Index hash ref
$currentAttrs: Hash refs of the attributes valid
for the current group.
=cut
sub _buildAttrIndex{
my ($self, $index, $currentAttrs) = @_;
# Take care of any attributes in the current group
my @attrs = $self->attrs;
my @attrValues = $self->attrGet(@attrs);
# Get the group name
my $groupName = $self->nameGet;
my %indexElement; # element of the index for this group
%indexElement = %$currentAttrs; # Initialize index element
# with attributes valid at the
# group above
# Add (or overwrite) attributes for this group
# i.e. local group attributes take precedence over
# higher-level attributes
@indexElement{@attrs} = @attrValues;
$index->{$groupName} = \%indexElement;
# Now Do any subgroups:
my @subGroups = $self->groups;
my $subGroup;
foreach $subGroup(@subGroups){
$self->group($subGroup)->_buildAttrIndex($index,\%indexElement);
}
}
=head2 IDget
=for ref
Returns the HDF5 library ID for this object
B<Usage:>
=for usage
my $ID = $groupObj->IDget;
=cut
sub IDget{
my $self = shift;
return $self->{ID};
}
=head2 nameGet
=for ref
Returns the HDF5 Group Name for this object. (Relative to the root group)
B<Usage:>
=for usage
my $name = $groupObj->nameGet;
=cut
sub nameGet{
my $self = shift;
return $self->{name};
}
1;